One of my favorite things about running the press, totally non-poetry related, is designing the cover art. Alot of times, the poet already has particular artwork or designers in mind, which works as well, and some of of our most gorgeous covers have come about this way. Other times, they have general ideas or feels that generate something. Usually, since my art skills are mostly limited to collage (I suck at drawing and am not much better with paints), I will try to find something simple that works well with the poems--vintage illustrations or photos, stock photography (ideally that doesn't look like stock photography), manipulated public domain images. Sometimes, just typographical elements.
In a couple of recent cases I've gotten to make specific peices of art for covers, which I love doing, including a collage for Becky Peterson's Art Deco Set Design Curtains Falling (as seen above, an initial collage that sparked an entire series I am now playing with) and Amanda Ackerman's Short Stones, both underway currently and due out shortly. While my design skills and software are pretty limited (no sustained access to photoshop and I'm a spaz w/ InDesign) it's always something I love doing, even if it's just adding text to artwork or choosing fonts and layout strategies.